In a curved apron conveyor of this kind known from U.S. Pat. No. 3,513,964 guiding surfaces welded under the individual plate members, extending parallel to the longitudinal axis of the conveyor and connected by means of cross-pieces or ribs, are used to guide the belt conveyor on its curved path. For this purpose the guiding surfaces are inclined and abut against the similarly inclined, stationary guide rails of the apron conveyor. The angle of inclination is selected so that the plate members cannot lift off upwards. In the case of right-angled guide rails and guiding surfaces arranged perpendicular to the plate plane it is known to prevent the apron conveyor from lifting off by means of guide tongues on the guiding surfaces, bent outwardly at right angles, that engage under the rails.
Furthermore, it is known from German Auslegeschrift No. 22 37 600 to make the guiding surfaces of a plate member serving for guidance on stationary slide bars or rails from guiding surfaces bent downwards substantially perpendicular to the plate member. The plate member and the guiding surfaces comprise an integral sheet metal blank and the bent edges of the guiding surfaces lie within the area of the plate member. The known apron conveyors, however have the disadvantage that goods being conveyed that are liable to break during the operation, such as for example broken glass, can stick between the plate members and cause damage.